Sequence valve

Abstract

A sequence valve for directing fluid pressure is provided, having a fluid pressure inlet, a first actuator outlet with associated vent port, and a second actuator outlet with an associated vent port. A spool is movably mounted within the body for selective direction of fluid pressure applied to the inlet to either of the actuator outlets or selectively to bleed pressure applied to either of the actuator outlets through respective vent portions in a predetermined sequence.

I claim: 
     
       1. An apparatus for directing fluid pressure from a primary source to at least two actuators, comprising: a body;   at least one inlet into said body for admitting primary source pressure;   at least one first actuator outlet in said body;   at least one second actuator outlet in said body;   spool means selectively movable in said body manually and by fluid pressure from the primary source for selective sequential alignment of the pressure at said inlet to said first and then second actuator outlets as said spool means moves in a first direction, and for selective sequential venting of the pressure at said first and second actuator outlets from said body and isolation of said inlet as said spool means moves in a second direction, opposite said first direction, upon loss of fluid pressure at said inlet;   said spool means selectively manually operable in said second direction to vent at least one of said outlets while isolating it from said inlet.   
     
     
       2. The apparatus of claim 1, wherein said spool means is constructed of an upper and a lower segment selectively movable in tandem and independently. 
     
     
       3. The apparatus of claim 1, wherein said body is formed having a plurality of inlet passages providing fluid communication from said inlet to said spool means. 
     
     
       4. The apparatus of claim 3, wherein said spool means has a first cross-sectional area having an upper and a lower surface, said upper surface of said first cross-sectional area being in flow communication with a first of said inlet passages. 
     
     
       5. The apparatus of claim 1, further comprising: an actuator connected to said first actuator outlet; and   an actuator connected to said second actuator outlet.   
     
     
       6. An apparatus for directing fluid pressure from a primary source to at least tow actuators, comprising: a body;   at least one inlet in said body for admitting primary source pressure; at least one first actuator outlet in said body;     at least one second actuator outlet in said body;   spool means selectively movable in said body manually and by fluid pressure from the primary source for selective sequential alignment of the pressure at said inlet to said first and then said second actuator outlets and for selective venting of the pressure at said first and second actuator outlets from said body;   flow restriction means in fluid communication within said inlet for regulating the rate of fluid pressure transfer from said inlet to said spool means.   
     
     
       7. The apparatus of claim 6, further comprising: flow control means in fluid communication between said inlet and at lest one of said actuator outlets and automatically operable to permit or prohibit flow therebetween.   
     
     
       8. The apparatus of claim 6, further comprising: an actuator connected to said first actuator outlet; and   an actuator connected to said second actuator outlet.   
     
     
       9. An apparatus for directing fluid pressure from a primary source to at least one actuator, comprising: a body;   at least one inlet for admitting primary source pressure;   at least one first actuator outlet;   at least one second actuator outlet;   spool means selectively movable in said body for selectively sequential alignment of the pressure at said inlet to said first and second actuator outlets and for selective venting of the pressure at said first and second actuator outlets from said body;   said body is formed having a plurality of inlet passages providing fluid communication from said inlet to said spool means;   said spool means has a first cross-sectional area having an upper and a lower surface, said upper surface of said first cross-sectional area being in flow communication with a first of said inlet passages;   said spool means has a second cross-sectional area smaller than said first cross-sectional area;   a second of said inlet passages in said body providing fluid communication to said second cross-sectional area and said first actuator outlet from said inlet, whereupon application of fluid pressure to said inlet and through said first and second inlet passages results in opposing forces acting on said spool, producing a resultant force which moves said spool means from a first to a second position;   a first vent passage extending from said spool means to the outer surface of said body;   said spool means selectively permitting fluid communication between said second inlet passage and said first vent passage in said first position and blocking fluid communication between said second inlet passage and said first vent passage when said spool means in said second position;   said fluid pressure building up at said first actuator outlet as said spool means is driven from said first to said second positions.   
     
     
       10. The apparatus of claim 9, wherein: said spool means in formed having a plurality of segments, the lowermost segment of said spool means in formed having said first and second cross-sectional areas, said first vent passage extending to said lowermost spool means;   the uppermost segment of said spool means is in fluid communication with said inlet through a third inlet passage and is capable of movement selectively in tandem and independently of said lowermost segment of said spool means;   said second actuator outlet in fluid communication with said uppermost spool means through an outlet passage;   said uppermost spool means movable from a first position where said inlet is isolated from said outlet passage and a second position where said inlet is in flow communication with said outlet passage.   
     
     
       11. The apparatus of claim 10, further comprising: a second vent passage extending from the outer surface of said body to said uppermost spool means;   said uppermost spool means allowing flow communication from said second actuator outlet, through said outlet passage, to said second vent passage when said uppermost spool means is in said first position and isolating said second actuator outlet and said outlet passage from said second vent passage when said uppermost spool means is in said second position.   
     
     
       12. The apparatus of claim 11, further comprising: biasing means acting on said spool means to bias said uppermost and lowermost spool means into their respective said first positions in the absence of fluid pressure in said inlet.   
     
     
       13. The apparatus of claim 12, wherein: said biasing means applies a biasing force to said lower surface of said first cross-sectional area;   whereupon application of fluid pressure through said inlet, the pressure is also applied to said first and second inlet passages, which results in a force applied to said upper surface of said first cross-sectional area, which overcomes said biasing means and the force applied by fluid pressure to said second cross-sectional area, resulting in movement of said lowermost spool means from said first to said second position, independently of said uppermost spool means.   
     
     
       14. The apparatus of claim 13, further comprising: one-way flow means in said second inlet passage permitting fluid flow only in a direction from said inlet toward said first actuator outlet and said lowermost spool means;   whereupon decrease of fluid pressure from a first pressure to below a trigger point and with said uppermost spool means in said second position, said one-way flow means retains the first pressure against said second cross-sectional area as the fluid pressure on said first cross-sectional area declines to the trigger pressure, whereupon the combined forces of said biasing means and the first pressure acting on said second cross-sectional area overcome the opposing force of trigger pressure applied to said first cross-sectional area, resulting in movement of both said uppermost and lowermost spool means in tandem from their second to their first positions.   
     
     
       15. The apparatus of claim 14, wherein: said upper and lower spool means are configured when moving in tandem from their respective said second to first positions upon reduction of fluid pressure at said inlet to below a trigger point, to first isolate said second actuator outlet and said outlet passage from said inlet, then to permit fluid communication between said second actuator outlet and said outlet passage to said second vent passage, followed by permitting fluid communication between said first actuator outlet to said first vent passage.   
     
     
       16. The apparatus of claim 15, wherein: said uppermost and lowermost spool means simultaneously attain a position between their respective first and second positions where said inlet is isolated from said outlet passage, said outlet passage is isolated from said second vent passage, and said second inlet passage is isolated from said first vent passage.   
     
     
       17. The apparatus of claim 15, wherein: said uppermost spool means extends in part beyond said body, said extended portion allowing selective movement of said uppermost spool means between said first and second positions;   whereupon before initial application of fluid pressure to said inlet, said biasing means retains said uppermost spool means in said first position, and subsequent application of fluid pressure to said inlet results in said fluid pressure being first applied at said first actuator outlet as said lowermost spool means moves independently to its said second position, whereupon application of force to said extending part of said uppermost spool means results in a subsequent application of said fluid pressure from said inlet at said second actuator outlet.   
     
     
       18. The apparatus of claim 17, wherein: application of a biasing force to said extending portion of said uppermost spool means, urging it from said second to said first position while fluid pressure is applied to said inlet, results in the continued application of fluid pressure at said first actuator outlet, while pressure at said second actuator outlet is relieved by said uppermost spool means, allowing flow communication between said outlet passage and said second vent passage.   
     
     
       19. The valve of claim 18, further comprising: flow restriction means in said first inlet passage for controlling rate of movement of said lowermost spool between its first and second positions; and   relief means to prevent overpressure in said body.   
     
     
       20. The apparatus of claim 19, wherein: said relief means is a relief valve having an inlet in constant flow communication with said second inlet passage and an outlet in flow communication with said first vent passage;   said body and said lowermost spool means defining a variable-volume sealed chamber in which said biasing means is disposed, said chamber having its smallest volume when said lowermost spool means is in said second position;   said chamber being gas filled which, when compressed by movement of said lowermost spool to its said second position, exerts a force in the same direction as said biasing means on said lowermost spool means.   
     
     
       21. The apparatus of claim 20, further comprising: a first and second seal circumscribing said lowermost spool means and disposed respectively on each side of said first vent passage;   a third and fourth seal circumscribing said uppermost spool means and respectively mounted on each side of said second vent passage;   a fifth and sixth seal circumscribing said uppermost spool means and respectively mounted on each side of said third inlet passage;   said fourth and fifth seals also disposed respectively on each side of said first outlet passage;   said lowermost spool having a first spline thereon;   said uppermost spool having a second and third spline thereon, said splines allowing flow communication when straddling one of said seals and blocking fluid communication when in between two of said seals;   whereupon initial application of fluid pressure at said inlet moves said first spline from straddling said first seal to a position out from between said first and second seals;   said second spline straddles said fourth seal and said third spline is between said fifth and sixth seals when said uppermost spool means is in said first position;   said second spline is between said third and fourth seals and said third spline straddles said fifth seal when said uppermost spool means is in said second position.   
     
     
       22. The apparatus of claim 21, wherein said first, second, and third splines are disposed in a manner that upon reduction in fluid pressure at said inlet below a trigger point and with said uppermost spool initially in said second position, tandem movement of said uppermost and lowermost spool means results in said third spline first moving from a position where it straddles said fifth seal to a position between said fifth and sixth seals, then said second spline moving from a position where it is between said third and fourth seals to straddling said fourth seal, then said first spline moving from position where it is outside the span between said first and second seals to a position where it straddles said first seal. 
     
     
       23. The apparatus of claim 22, further comprising: a seventh seal circumscribing said lowermost spool means between said upper and lower surfaces of said first cross-sectional area, sealing at least in part said chamber wherein said biasing means are disposed; and   an eighth seal circumscribing said lowermost spool 10, means and disposed between said third and seventh seals;   said body formed having a second cavity partly defined by said upper surface of said first cross-sectional area, and said second cavity is sealed by said seventh and eighth seals and subject to volumetric changes upon movement of said lowermost spool means between said first and second positions;   said first inlet passage in flow communication with said second cavity.   
     
     
       24. An apparatus for directing fluid pressure from a primary source to at least two actuators, comprising: a body;   at least one inlet into said body for admitting primary source pressure;   at least one first actuator outlet in said body;   at least one second actuator outlet in said body;   spool means selectively movable in said body manually and by fluid pressure from the primary source for selective sequential alignment of the pressure at said inlet to said first and then second actuator outlets as said spool means moves in a first direction, and for selective sequential venting of the pressure at said first and second actuator outlets from said body and isolation of said inlet as said spool means moves in a second direction, opposite said first direction, upon loss of fluid pressure at said inlet;   said spool means selectively manually operable in said second direction to vent at least one of said outlets while isolating it from said inlet;   said body is formed having a plurality of inlet passages providing fluid communication from said inlet to said spool means;   said spool means has a first cross-sectional area having an upper and a lower surface, said upper surface of said first cross-sectional area being in flow communication with a first of said inlet passages;   said spool means has a second cross-sectional area smaller than said first cross-sectional area;   a second of said inlet passages in said body providing fluid communication to said second cross-sectional area and said first actuator outlet from said inlet, whereupon application of fluid pressure to said inlet and through said first and second inlet passage results in opposing forces acting in said spool, producing a resultant force which moves said spool means from a first to a second position.